Develop Reference

ListBox display multiple selected items

I have here a ListBox which shall show serveral items where some of them are selected.
<ListBox IsEnabled="False" x:Name="SecondaryModelSelector" SelectionMode="Extended" SelectedItem="{Binding Path=DataContext.SelectedSecondaryModels, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ContentControl}, Mode=OneWay}" ItemsSource="{Binding Path=DataContext.AvailableModels, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ContentControl}}" >
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<Label Content="{Binding Name}" Margin="5,0,5,0"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
The selected items are set in a ComboBox and thus the ListBox is disabled and Mode=OneWay to disable selection in the ListBox itself.
The Template looks like this:
<Style x:Key="MyListBoxItem" TargetType="ListBoxItem">
<Setter Property="SnapsToDevicePixels" Value="true" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListBoxItem">
<Border x:Name="Border" Padding="2">
<ContentPresenter />
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsSelected" Value="true">
<Setter TargetName="Border" Property="Background" Value="Blue"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="MyListBoxBorder" TargetType="{x:Type ListBox}">
<Setter Property="ItemContainerStyle" Value="{StaticResource MyListBoxItem}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListBox">
<Border x:Name="OuterBorder">
<ScrollViewer Margin="0" Focusable="false">
<StackPanel Margin="2" IsItemsHost="True" />
</ScrollViewer>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
The problem is now, that I cannot display multiple selected items, i.e. the background does not turn blue. Showing only one selected item is no problem.
Works (but shows only one selected item...)
public Cpu SelectedSecondaryModels
{
get { return SelectedGlobalVariable.SecondaryModels.FirstOrDefault(); }
}
Does not work:
public ObservableCollection<Model> SelectedSecondaryModels
{
get { return new ObservableCollection<Model>(SelectedGlobalVariable.SecondaryModels); }
}
I have no errors, so how can I show multiple selected items?
I tried SelectedItems instead of SelectedItem instead, but this is read-only field.
When I allow to select items in the ListBox than the blue background appears, and binding throws errors as there is no setter method.

The SelectedItem property cannot be bound to a collection of several items to be selected.
And as you have already noticed, SelectedItems is a read-only property.
You could use an attached behaviour to work around this. Please refer to this blog post and this example for more information about how to do this.
You will also find some solutions here:
Bind to SelectedItems from DataGrid or ListBox in MVVM

How to remove ContextMenu border

So im trying to make button appear on right click in my ListBox.
<ListBox Grid.Column="1" Margin="358,44,20,63" Name="scriptbox" Background="#FF282828" Foreground="White" SelectionChanged="Scriptbox_SelectionChanged" BorderThickness="0">
<ListBox.ContextMenu>
<ContextMenu>
<MenuItem
Template="{DynamicResource MenuItemTemplate}"
Header="Delete"
Click="MenuItemDelete_Click" >
</MenuItem>
</ContextMenu>
</ListBox.ContextMenu>
This is my MenuItem template.
<ControlTemplate TargetType="{x:Type MenuItem}" x:Key="MenuItemTemplate">
<Border x:Name="Border" Background="#FF282828" Padding="30,5,30,5" BorderThickness="0" Margin="0">
<ContentPresenter ContentSource="Header" x:Name="HeaderHost" RecognizesAccessKey="True" />
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsHighlighted" Value="true">
<Setter Property="Background" TargetName="Border" Value="#51544e"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<ItemsPanelTemplate x:Key="MenuItemPanelTemplate">
<StackPanel Margin="-3,0,0,0" Background="White"/>
</ItemsPanelTemplate>
<Style TargetType="{x:Type MenuItem}">
<Setter Property="ItemsPanel" Value="{StaticResource MenuItemPanelTemplate}"/>
</Style>
Everything is fine but there is white border all around the button.

What you recognize as a white border is the ContextMenu itself that contains your MenuItems. Try adding more buttons and changing the Background and BorderBrush of the ContextMenu and you will see.
<ContextMenu Background="Red" BorderBrush="Blue">
Changing the brushes like this will lead to this result, which makes it obvious.
If you create a custom control template for your MenuItems you should probably do so for the ContextMenu, too, if only setting brushes does not fit your requirements. As you can see in the example, there is still a vertical white line that is part of the default control template, that you might want to get rid of. You can start from this example, although it is neither the default template nor complete. Look at this related post for guidance on how to extract the default control template for ContextMenu if you need it.

Command binding to top-level MenuItem of Menu doesn't work

I'm learning WPF and developing a dynamic Menu which is driven by data binding of it's ItemsSource to an ObservableCollection. To do this I have a simple MenuItemViewModel and a HierarchicalDataTemplate for automatic binding of MenuItems to it.
The problem I have is that Command property doesn't work for top level menu items. Despite it is set, a MenuItem doesn't react on mouse click and doesn't get disabled if Command cannot be executed. Simply it's like it's not getting bound.
For lower level menu items though, it works as intended. I think this should be a problem of my HierarchicalDataTemplate but I can't find it, because as I see there's no code in template which might affect command binding of only top-level MenuItems.
MenuItemViewModel implements INotifyPropertyChanged and contains following public properties:
string Text
Uri ImageSource
ICommand Command
ObservableCollection<MenuItemViewModel> Children
HierarchicalDataTemplate for MenuItem in my Window.Resources is as follows:
<HierarchicalDataTemplate DataType="{x:Type common:MenuItemViewModel}"
ItemsSource="{Binding Path=Children}">
<HierarchicalDataTemplate.ItemContainerStyle>
<Style TargetType="MenuItem">
<Setter Property="Command"
Value="{Binding Command}" />
</Style>
</HierarchicalDataTemplate.ItemContainerStyle>
<StackPanel Orientation="Horizontal">
<Image Source="{Binding ImageSource}" />
<TextBlock Text="{Binding Text}" VerticalAlignment="Center"/>
</StackPanel>
</HierarchicalDataTemplate>
Can you please point me on my mistake?
EDIT: Top-level MenuItem doesn't contain any children (i.e. Children collection of associated ViewModel is empty).

Thanks to #sTrenat comment I've come to solution below.
<Menu.Resources>
<!-- cancel sharing of image so Icon will work properly -->
<Image x:Key="MenuIcon" Source="{Binding ImageSource}" x:Shared="False"/>
</Menu.Resources>
<Menu.ItemContainerStyle>
<Style TargetType="{x:Type MenuItem}"
BasedOn="{StaticResource {x:Type MenuItem}}">
<Setter Property="Header" Value="{Binding Text}" />
<Setter Property="Icon" Value="{StaticResource MenuIcon}"/>
<Setter Property="Command" Value="{Binding Command}"/>
<Setter Property="ItemsSource" Value="{Binding Children}" />
<!-- centering MenuItem's Header -->
<Setter Property="HeaderTemplate">
<Setter.Value>
<DataTemplate>
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" Content="{Binding}" />
</DataTemplate>
</Setter.Value>
</Setter>
<!-- setting Icon to null when ImageSource isn't specified -->
<Style.Triggers>
<DataTrigger Binding="{Binding ImageSource}"
Value="{x:Null}">
<Setter Property="Icon" Value="{x:Null}"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Menu.ItemContainerStyle>

WPF ComboBox EditTemplate - TextBox border is not going away

I am using a DEVExpress combobox and have enabled type ahead (Auto search functioanlity). In combo box I am showing two things. First item is an image and second item is a value(id).
Mine problem is that the value border is getting outside to combo box while showing at UI at run time. I tried setting margin but its of no use. My application is having option to select theme and for some of the theme its getting hazy.
Any idea how to get rid of this ?
see the first one is looking fine however the below one is bit hazy if i change the theme.
I am using below code for the same.
<dvEx:ComboBoxEdit.EditTemplate>
<ControlTemplate>
<StackPanel Orientation="Horizontal">
<Image Source="{Binding Path=(dxe:BaseEdit.OwnerEdit).SelectedItem.Image, RelativeSource={RelativeSource Self}}" Margin="8, 0, 4, 0"/>
<TextBox x:Name="PART_Editor" BorderBrush="Transparent"/>
</StackPanel>
</ControlTemplate>
</dvEx:ComboBoxEdit.EditTemplate>
<dvEx:ComboBoxEdit.ItemTemplate>
<DataTemplate DataType="{x:Type vm:DesignSelectViewModel}">
<StackPanel Orientation="Horizontal">
<Image Source="{Binding Image}" Margin="8, 0, 4, 0"/>
<TextBlock Text="{Binding Name}"/>
</StackPanel>
</DataTemplate>
</dvEx:ComboBoxEdit.ItemTemplate>

To accomplish your task I suggest you to override the TextBox.Template as follows to make it theme-independent and remove it's focused state (border and background):
<TextBox x:Name="PART_Editor">
<TextBox.Template>
<ControlTemplate TargetType="{x:Type TextBox}">
<Grid x:Name="Root" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}">
<ScrollViewer x:Name="PART_ContentHost" Margin="1" Padding="{TemplateBinding Padding}"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsReadOnly" Value="True">
<Setter Property="Opacity" TargetName="PART_ContentHost" Value="0.75"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Opacity" TargetName="Root" Value="0.5"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</TextBox.Template>
</TextBox>
Related MSDN article: TextBox Styles and Templates

Custom ListBox in WPF

I am trying to create a custom ListBox control in WPF for a chat Messenger. I am using an ellipse to show the online/offline user. The ellipse is to be displayed on left and some text in center of the ListBoxItem.
I want to set the ellipse fill propert to red/green based on some variable.
This is what I have done :
<ListBox Name="myList" HorizontalAlignment="Left" Height="232" Margin="117,74,0,0" VerticalAlignment="Top" Width="207">
<ListBox.ItemTemplate>
<DataTemplate>
<DockPanel>
<Ellipse Name="ellipse" Fill="Red" DockPanel.Dock="Left">
<Ellipse.Triggers>
<Trigger Property="{Binding Online}" Value="True">
<Setter TargetName="ellipse" Property="Ellipse.Fill" Value="Green"/>
</Trigger>
</Ellipse.Triggers>
</Ellipse>
<TextBlock Text="{Binding text}"></TextBlock>
</DockPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
and in the code :
myList.Items.Add(new { text="Hello",Online="True" });
I am getting an error as
Cannot find the static member 'FillProperty' on the type 'ContentPresenter'.
What am I doing wrong here?

Obviously this is wrong: Property="{Binding Online}"
Also you should use a Style for triggers, no need to set TargetName, and you need to take precedence into consideration, and use a Setter for the default value.

you are actually misleading WPF with some of these concerns.
Binding A property on trigger will not work. you have to use DataTrigger insteed of Triggers.
Implementing Trigger on the Fly for any control. most of the times not work. So go with Styles.
While you are creating Ellipse in template make sure you have created enough size for it. So that can be visible to users.
try this.
<Window.Resources>
<Style x:Key="elstyle" TargetType="Ellipse">
<Setter Property="Height" Value="5"/>
<Setter Property="Width" Value="5"/>
<Setter Property="Fill" Value="Red"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Online}" Value="true">
<Setter Property="Fill" Value="Green"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Window.Resources>
<Grid>
<ListBox x:Name="myList" HorizontalAlignment="Left" Height="232" Margin="117,74,0,0" VerticalAlignment="Top" Width="207">
<ListBox.ItemTemplate>
<DataTemplate>
<DockPanel>
<Ellipse Name="ellipse" Margin="5" DockPanel.Dock="Left" Style="{DynamicResource elstyle}">
</Ellipse>
<TextBlock Text="{Binding Name}"></TextBlock>
</DockPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
code behind .
public MainWindow()
{
Random r = new Random();
InitializeComponent();
for (int i = 0; i < 10; i++)
{
myList.Items.Add(new { Name = "Name" + i.ToString(), Online = Convert.ToBoolean(r.Next(-1, 1)) });
}
}

You need to set the initial colour via a Setter and not in XAML. For more information and see this question: Change the color of ellipse when mouse over

there are a few issues in your XAML
set the size of your Ellipse
you need to use Style instead of Ellipse.Triggers
set your Fill color in your Style if you wane be able to change it in XAML by some condition
here an working example for your problem
<DataTemplate>
<!--<DockPanel> juste because i like StackPanel-->
<StackPanel Orientation="Horizontal">
<!--<Ellipse Name="ellipse" Fill="Red" DockPanel.Dock="Left">-->
<Ellipse Name="ellipse" Width="15" Height="15">
<!--<Ellipse.Triggers>-->
<Ellipse.Style>
<Style TargetType="Ellipse">
<Setter Property="Fill" Value="Red"/>
<Style.Triggers>
<!--<Trigger Property="{Binding Online}" Value="True">-->
<DataTrigger Binding="{Binding Online}" Value="True">
<Setter Property="Fill" Value="LimeGreen"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Ellipse.Style>
</Ellipse>
<TextBlock Text="{Binding text}"/>
</StackPanel>
</DataTemplate>